Re: [PATCH v2 05/28] fsnotify: new tracepoint in fsnotify()

Jan Kara
2026-04-17T11:49:12Z

On Thu 16-04-26 10:35:06, Jeff Layton wrote:
> Add a tracepoint so we can see exactly how this is being called.
>
> Signed-off-by: Jeff Layton <jlayton@kernel.org>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

Honza

> ---
> fs/notify/fsnotify.c | 5 ++++
> include/trace/events/fsnotify.h | 51 +++++++++++++++++++++++++++++++++++++++++
> include/trace/misc/fsnotify.h | 35 ++++++++++++++++++++++++++++
> 3 files changed, 91 insertions(+)
>
> diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
> index 9995de1710e5..5448738635f6 100644
> --- a/fs/notify/fsnotify.c
> +++ b/fs/notify/fsnotify.c
> @@ -14,6 +14,9 @@
> #include <linux/fsnotify_backend.h>
> #include "fsnotify.h"
>
> +#define CREATE_TRACE_POINTS
> +#include <trace/events/fsnotify.h>
> +
> /*
> * Clear all of the marks on an inode when it is being evicted from core
> */
> @@ -504,6 +507,8 @@ int fsnotify(__u32 mask, const void *data, int data_type, struct inode *dir,
> int ret = 0;
> __u32 test_mask, marks_mask = 0;
>
> + trace_fsnotify(mask, data, data_type, dir, file_name, inode, cookie);
> +
> if (path)
> mnt = real_mount(path->mnt);
>
> diff --git a/include/trace/events/fsnotify.h b/include/trace/events/fsnotify.h
> new file mode 100644
> index 000000000000..341bbd57a39b
> --- /dev/null
> +++ b/include/trace/events/fsnotify.h
> @@ -0,0 +1,51 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#undef TRACE_SYSTEM
> +#define TRACE_SYSTEM fsnotify
> +
> +#if !defined(_TRACE_FSNOTIFY_H) || defined(TRACE_HEADER_MULTI_READ)
> +#define _TRACE_FSNOTIFY_H
> +
> +#include <linux/tracepoint.h>
> +
> +#include <trace/misc/fsnotify.h>
> +
> +TRACE_EVENT(fsnotify,
> + TP_PROTO(__u32 mask, const void *data, int data_type,
> + struct inode *dir, const struct qstr *file_name,
> + struct inode *inode, u32 cookie),
> +
> + TP_ARGS(mask, data, data_type, dir, file_name, inode, cookie),
> +
> + TP_STRUCT__entry(
> + __field(__u32, mask)
> + __field(unsigned long, dir_ino)
> + __field(unsigned long, ino)
> + __field(dev_t, s_dev)
> + __field(int, data_type)
> + __field(u32, cookie)
> + __string(file_name, file_name ? (const char *)file_name->name : "")
> + ),
> +
> + TP_fast_assign(
> + __entry->mask = mask;
> + __entry->dir_ino = dir ? dir->i_ino : 0;
> + __entry->ino = inode ? inode->i_ino : 0;
> + __entry->s_dev = dir ? dir->i_sb->s_dev :
> + inode ? inode->i_sb->s_dev : 0;
> + __entry->data_type = data_type;
> + __entry->cookie = cookie;
> + __assign_str(file_name);
> + ),
> +
> + TP_printk("dev=%d:%d dir=%lu ino=%lu data_type=%d cookie=0x%x mask=0x%x %s name=%s",
> + MAJOR(__entry->s_dev), MINOR(__entry->s_dev),
> + __entry->dir_ino, __entry->ino,
> + __entry->data_type, __entry->cookie,
> + __entry->mask, show_fsnotify_mask(__entry->mask),
> + __get_str(file_name))
> +);
> +
> +#endif /* _TRACE_FSNOTIFY_H */
> +
> +/* This part must be outside protection */
> +#include <trace/define_trace.h>
> diff --git a/include/trace/misc/fsnotify.h b/include/trace/misc/fsnotify.h
> new file mode 100644
> index 000000000000..a201e1bd6d8c
> --- /dev/null
> +++ b/include/trace/misc/fsnotify.h
> @@ -0,0 +1,35 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Display helpers for fsnotify events
> + */
> +
> +#include <linux/fsnotify_backend.h>
> +
> +#define show_fsnotify_mask(mask) \
> + __print_flags(mask, "|", \
> + { FS_ACCESS, "ACCESS" }, \
> + { FS_MODIFY, "MODIFY" }, \
> + { FS_ATTRIB, "ATTRIB" }, \
> + { FS_CLOSE_WRITE, "CLOSE_WRITE" }, \
> + { FS_CLOSE_NOWRITE, "CLOSE_NOWRITE" }, \
> + { FS_OPEN, "OPEN" }, \
> + { FS_MOVED_FROM, "MOVED_FROM" }, \
> + { FS_MOVED_TO, "MOVED_TO" }, \
> + { FS_CREATE, "CREATE" }, \
> + { FS_DELETE, "DELETE" }, \
> + { FS_DELETE_SELF, "DELETE_SELF" }, \
> + { FS_MOVE_SELF, "MOVE_SELF" }, \
> + { FS_OPEN_EXEC, "OPEN_EXEC" }, \
> + { FS_UNMOUNT, "UNMOUNT" }, \
> + { FS_Q_OVERFLOW, "Q_OVERFLOW" }, \
> + { FS_ERROR, "ERROR" }, \
> + { FS_OPEN_PERM, "OPEN_PERM" }, \
> + { FS_ACCESS_PERM, "ACCESS_PERM" }, \
> + { FS_OPEN_EXEC_PERM, "OPEN_EXEC_PERM" }, \
> + { FS_PRE_ACCESS, "PRE_ACCESS" }, \
> + { FS_MNT_ATTACH, "MNT_ATTACH" }, \
> + { FS_MNT_DETACH, "MNT_DETACH" }, \
> + { FS_EVENT_ON_CHILD, "EVENT_ON_CHILD" }, \
> + { FS_RENAME, "RENAME" }, \
> + { FS_DN_MULTISHOT, "DN_MULTISHOT" }, \
> + { FS_ISDIR, "ISDIR" })
>
> --
> 2.53.0
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR